section name header

Introduction ⬇

Tidal Volume (VT)

VT measures the amount of air inspired during normal respiration, without any effort. This measurement is important to assess when weaning a patient from a ventilator, to ensure that the patient has adequate volume of air when taking a normal breath.

Procedure ⬆ ⬇

  1. Have the patient either sit or stand. Place nose clips on the nose and instruct the patient to breathe normally through a mouthpiece/filter (bacterial/viral) combination into the spirometer.

  2. Repeat step 2 two or more times until the two best values are within 5% of each other. Select the largest inspired volume value.

Clinical Implications ⬆ ⬇

  1. Low VT indicates inadequate oxygen/carbon dioxide exchange.

  2. Low VT during ventilator weaning trials may indicate inability of the patient to be successfully removed from ventilator support.

Interventions ⬆ ⬇

Pretest Patient Care

  1. Instruct the patient about the purpose and procedure of the test and the need for patient cooperation.

  2. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed.

  2. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Reference Values ⬆

Normal